The invention relates to an optical waveguide coupler with a number of elongated narrow optical waveguide strips, each of which has a front area, a center area and a coupling area, in that the center area respectively comprises a transition area toward the corresponding front area, or toward the coupling area in such a way that the distance between two adjoining strips is greater in the front area than the thickness of the narrow strips, and wherein the strips form a stack in the coupling area. The invention further relates to a method of producing such an optical waveguide coupler.
A structure of optical waveguides of this type is known from U.S. Pat. No. 5,343,546. In this embodiment, the individual optical waveguides are held without substrates, wherein each individual optical waveguide itself is turned in such a way that a transition from a vertical to a horizontal position results from this.
A method of producing optical fibers is furthermore known from U.S. Pat. No. 5,173,097. In accordance with this method, optical fibers of very small dimensions are produced by drawing the fibers while they are in the plastic state. The thin fibers can then be employed in a stacked form for actual uses, such as for producing optical waveguide couplers, for example.
A further method of producing optical waveguides is known from U.S. Pat. No. 5,963,687, which was published during the priority period. In accordance with this method, a glass-producing material is deposited with the aid of a very thin flame on a substrate, and its thickness is achieved by means of a suitable relative movement between the flame and the substrate.
Sometimes optical waveguide couplers are used in connection with miniaturized optical systems. Such waveguide couplers are components which make it possible to couple the light emitted by a number n of transmitting elements, in particular laser diodes, into at least one optical waveguide. Such a waveguide coupler can, for example, have a number n of inputs and a single output. These inputs and outputs of known optical waveguide couplers are themselves optical waveguides per se. Only such optical waveguides make miniaturization possible, because it is not possible in actuality to represent a number n of emitting diode surfaces, for example by means of a lens and mirror system, in a very small space on the core diameter of an output optical waveguide.
Such optical waveguide couplers operate very well per se, but are relatively elaborate.
It is therefore the object of the invention to produce an optical waveguide coupler which is less elaborate.
This object is attained in an advantageous manner by means of an optical waveguide coupler with a number of elongated narrow optical waveguide strips, each of which has a front area, a center area and a coupling area. The center area comprises a transition area toward the corresponding front area, or toward the coupling area such that the distance between two adjoining strips is greater in the front than the thickness of the narrow strips, and the strips form a stack in the coupling area. The optical waveguide coupler is constituted by a structure of a substrate with pits and strips between the pits. The strips in the form of the optical waveguide strips comprise at least partially a material of the substrate, or an optical waveguide material, which constitutes the optical waveguide strips, is embedded in the pits.
It is a further object of the invention to provide a method for producing an optical waveguide coupler.
This object is attained by means of the method in for producing an optical waveguide coupler in which for producing a positive structure, a desired number of strips with lateral walls between the pits is created by forming pits in a substrate, and subsequently the pits are filled with a filler material. Alternatively, for producing a negative structure a number of pits corresponding to the desired number of strips is produced in a substrate, and then these pits are filled with a transparent filler material, so that the actual optical lightwave strips are created.
The optical waveguide coupler in accordance with the invention combines in an advantageous manner, the light output from n transmitting elements basically without output losses. Therefore the structural outlay for such systems can be significantly reduced, which in the end permits the realization of Microsystems.
Further advantageous embodiments of the invention ensue from the further dependent claims.
The invention will be explained by way of example in what follows, making reference to the drawings.